Support is requested for a symposium at the 24th Annual Meeting of the Environmental Mutagen Society of America (EMS) to be held at the Norfolk Waterside Marriott, Norfolk, Virginia, April 17-23, 1992. The symposium, entitled "Female Germ Cell Development and Toxicology" is organized by Dr. Philip C. Hanawalt and Dr. Walderico M. Generoso and it will be co-chaired by Dr. Jack Bishop and Dr. Richard Tasca. This symposium will bring to the attention of a major segment of environmental genetic toxicologists: Issues of concern regarding women's reproductive health, such as infertility and birth defects, that may be caused by genetic and environmental factors; the many recent, dramatic advances in molecular genetics and in cellular physiology which now make possible the application of high resolution technologies to better understand the detrimental effects of genetic and environmental factors upon female germ cell development; and applications of the technologies in research on female germ cell toxicities directed toward understanding the causes and prevention of infertility and birth defects. The invited speakers are well-known investigators in the fields of mammalian germ cell biology and toxicology. They will make 30 to 40-minute presentations with adequate time for questions and discussion in the 3-hour symposium session.